HOOKEK ON WELWITSCHIA. 
203 
school-boys as touchwood. Without attempting to give a detailed 
description of the plant here, which it would be impossible to render 
intelligible without copious drawings, we shall indicate and briefly 
comment upon some of the main exceptional features which it pre¬ 
sents. The general aspect of the trunk first strikes the attention. 
It is, as was described by Welwitsch, obconical with a flattened or 
concave top. The largest specimens which have as yet reached 
England, measure about 2 ft. in length and 4J ft. round the discoid 
top, one specimen weighing about 30 lbs. Many dry, leathery, 
tattered ribbons hang all round the margin of this disc, which, when 
the plant was growing, was raised but a few inches above the level 
of the ground. Examining these thongs more closely we find that 
they are, as the discoverer describes them, really but one pair of 
leaves split up longitudinally. The thongs sometimes separate to 
the base, and are then further removed from each other by intersti¬ 
tial growth of the circumference of the stock; but examining a suite 
of specimens from the youngest sent home, there can remain no 
doubt that usually they are referable to but a single pair of leaves, 
and that this pair is persistent. It remains to be demonstrated by 
actually germinating the seeds, that they are in reality the cotyle¬ 
dons of the embryo, but we think Dr. Hooker is quite justified in 
telling us there can be little doubt that such is the case. 
The bases of these dry leaves are enclosed in two horizontal 
grooves of 1 in. in depth, closely fitting and clasping the leaf. 
Each groove extends about half round the periphery of the disc. In 
one of the youngest examples received, with a diameter not exceed¬ 
ing If in. the leaf-grooves are already about \ in. deep. 
This singular structure of axis and leaf constitutes a very remark¬ 
able feature. The internal anatomy of these organs, also, is as ano¬ 
malous and unlike aught previously known, as any dream could 
picture. The lower portion of the older specimens, where it tapers 
down into the long tap-root, resembles, when vertically torn in twain, 
a mass of hempen yarn. Higher up in the thick part of the stock, 
where the cellular tissue is less decayed and living, the wood is 
firmer, though largely made up of the hempen element (the bast, or 
liber-layers) of the vascular bundles, which twist and twine in any 
sectional face, apparently in every direction. But if the vertical 
section be more carefully made, say at right angles to one of the 
leaves, and at a little distance within the margin of the disc from 
which it is given off, some order is recognisable, especially along a 
stratum about an inch or so below the crown or surface of the disc. 
This stratum consists of the distinct closely packed laterally com¬ 
pressed vascular cords left behind by the leaf-base as it became re¬ 
moved from the centre. These cords are continuous directly into 
the leaf, and form the unbranching veins which run along it, though 
unseen from the surface. Erom this stratum which is usually more 
or less cup-shaped, and nearly equidistant from the surface of the 
crown, bundles are given off into the crusty mass above, from which 
